Minelab SD2200 problem!

[Mechanic]

Hi Orbit,

The burned part is 6n03L. But why did it burn?
Make sure there are no bad electro caps on the board.
You can power the detector up still by just connecting the D and S pads of the fet, but use a current limited power supply.
Make sure the gate pin goes up to 5+ once the detector is powered on.
Detector ground is batt+ All measurements are referenced to batt+=gnd.
The detector should draw about 600mA with a coil.

I hope this helps..

Cheers Mick

[Orbit]

Thank you Mick ! Write what's up I removed the color with plate ninety percent the next day I will try to change burned part !

[Orbit]

After cleaning paints at the output of first op amp there was no signal I replaced him out with NE 5534 since I had him I'm not sure whether the original AD 797 or NE5534 in any case detector gives signs of recovery actually gets the impression that works normally touching input or touch IRF 640 or SK 216, the headphones obtain normal sound Minelab as it should , be but when you connect coil detector blocking and more I have no signal the channels such that when working when the voltage is raised through chopper , means without working and with coil not working ?!

[Mechanic]

Please check the coil tx, make sure the flyback is about 180v. Also check the gate pin on the 2sk. There is a high chance that the 2sk fet might be fried.
The opamp you replaced should be ad797, but for now the 5534 will do.
Check the output from TP304 in the front end and post a photo, you should be able to get your voltage scale down to 50mv/div..

Cheers

[Orbit]

Thanks Mick! I will write and I will put a photo the oscillogrammes the measuring point TP304, flyback voltage is about 180v problem occurs when the connects tx actually when coil elapsed current then receiver blocking I think there is a possibility that the FET 2sk 216 burned but hard to find I in my country I'll have to wait to buy from Germany Only if a replacement find with my country Good thing can be measured and keep track lines without this colors , (to point out when present flyback voltage in that moment,blocking receiver and if no flyback voltage then the receiver works) !?

[Bill512]

After cleaning paints at the output of first op amp there was no signal I replaced him out with NE 5534 since I had him I'm not sure whether the original AD 797 or NE5534 in any case detector gives signs of recovery actually gets the impression that works normally touching input or touch IRF 640 or SK 216, the headphones obtain normal sound Minelab as it should , be but when you connect coil detector blocking and more I have no signal the channels such that when working when the voltage is raised through chopper , means without working and with coil not working ?!

Hi Orbit, can you see the values of these big red capacitors? (WIMA?).
The sd2200 has 4 channels? (in contrary with the known 2 channels on SD2000)

[Orbit]

Capacitors values 4 x 1,5uf you 4 channels !

[Bill512]

Capacitors values 4 x 1,5uf you 4 channels !

thanks for the info.
I was expecting to be somewhere at 4.7-6.8uF ,because of their size.
It appears that are a higher voltage type than those from the sd2000.

[Orbit]

I want to publicly thank a lot my friend for the great help about repairs SD2200D Mechanic respectively Michael ,finally Minelab working correctly .

[N@SKO]

Orbit what you use to clean the PCB's from white paint?

[Orbit]

It is called SKID for paint !
I'll paint you tomorrow but I can send you to ! (PAINT REMOVER) !

[N@SKO]

Thank you very much!

[Xtrem]

Hi to all
I have a sd2200d with a problem , with no coil connected , it seems that
all the tunning knobs are working, with coil connected ,machine is working, it catches
metal parts on the air, but many knobs dont make anything, i can not tune the
threshold , only the tone pot is working and the tune button.
I have tried with 2 coils ,one DD 11" and one 18" mono, on both the same problem.
thank you.

[Mechanic]

Hi Xtrem,

Are you trying to run this unit around power, phone and other interference sources?
You need to be at least several hundred meters away from interference sources and the threshold tone should be steady, you can adjust it then.

Cheers Mick

[Xtrem]

Thank you Mick
yes ,i run this on very bad contitions about interference, i hope this is the problem,
i ask here because Ivconic could run this machine inside.
At weekend i make outside tests.
Savvas.